OBJECTIVE

Trigeminal neuralgia (TN) is a neuropathic pain disorder characterized by severe, lancinating facial pain that is commonly treated with neuropathic medication, percutaneous rhizotomy, and/or microvascular decompression (MVD). Patients who are not found to have distinct arterial compression during MVD present a management challenge. In 2013, the authors reported on a small case series of such patients in whom glycerin was injected intraoperatively into the cisternal segment of the trigeminal nerve. The objective of the authors’ present study was to report their updated experience with this technique to further validate this novel approach.

METHODS

The authors performed a retrospective analysis of data obtained in patients in whom glycerin was directly injected into the inferior third of the cisternal portion of the trigeminal nerve. Seventy-four patients, including 14 patients from the authors’ prior study, were identified, and demographic information, intraoperative findings, postoperative course, and complications were recorded. Fisher’s exact test, unpaired t-tests, and Kaplan-Meier survival curves using Mantel log-rank test were used to compare the 74 patients with a cohort of 476 patients who received standard MVD by the same surgeon.

RESULTS

The 74 patients who underwent MVD and glycerin injection had an average follow-up of 19.1 ± 18.0 months, and the male/female ratio was 1:2.9. In 33 patients (44.6%), a previous intervention for TN had failed. On average, patients had an improvement in the Barrow Neurological Institute Pain Intensity score from 4.1 ± 0.4 before surgery to 2.1 ± 1.2 after surgery. Pain improvement after the surgery was documented in 95.9% of patients. Thirteen patients (17.6%) developed burning pain following surgery. Five patients developed complications (6.7%), including incisional infection, facial palsy, CSF leak, and hearing deficit, all of which were minor.

CONCLUSIONS

Intraoperative injection of glycerin into the trigeminal nerve is a generally safe and potentially effective treatment for TN when no distinct site of arterial compression is identified during surgery or when decompression of the nerve is deemed to be inadequate.

OBJECTIVE

The purpose of this study was to investigate the spectrum of current treatment protocols for managing newly diagnosed chordoma of the mobile spine and sacrum.

METHODS

A survey on the treatment of spinal chordoma was distributed electronically to members of the AOSpine Knowledge Forum Tumor, including neurosurgeons, orthopedic surgeons, and radiation oncologists from North America, South America, Europe, Asia, and Australia. Survey participants were pre-identified clinicians from centers with expertise in the treatment of spinal tumors. The suvey responses were analyzed using descriptive statistics.

RESULTS

Thirty-nine of 43 (91%) participants completed the survey. Most (80%) indicated that they favor en bloc resection without preoperative neoadjuvant radiation therapy (RT) when en bloc resection is feasible with acceptable morbidity. The main area of disagreement was with the role of postoperative RT, where 41% preferred giving RT only if positive margins were achieved and 38% preferred giving RT irrespective of margin status. When en bloc resection would result in significant morbidity, 33% preferred planned intralesional resection followed by RT, and 33% preferred giving neoadjuvant RT prior to surgery. In total, 8 treatment protocols were identified: 3 in which en bloc resection is feasible with acceptable morbidity and 5 in which en bloc resection would result in significant morbidity.

CONCLUSIONS

The results confirm that there is treatment variability across centers worldwide for managing newly diagnosed chordoma of the mobile spine and sacrum. This information will be used to design an international prospective cohort study to determine the most appropriate treatment strategy for patients with spinal chordoma.

OBJECTIVE

Trigeminal neuralgia (TN) is characterized by intermittent, paroxysmal, and lancinating pain along the distribution of the trigeminal nerve. Microvascular decompression (MVD) directly addresses compression of the trigeminal nerve. The purpose of this study was to determine whether patients undergoing MVD as their first surgical intervention experience greater pain control than patients who undergo subsequent MVD.

METHODS

A retrospective review of patient records from 1998 to 2015 identified a total of 942 patients with TN and 500 patients who underwent MVD. After excluding several cases, 306 patients underwent MVD as their first surgical intervention and 175 patients underwent subsequent MVD. Demographics and clinicopathological data and outcomes were obtained for analysis.

RESULTS

In patients who underwent subsequent MVD, surgical intervention was performed at an older age (55.22 vs 49.98 years old, p < 0.0001) and the duration of symptoms was greater (7.22 vs 4.45 years, p < 0.0001) than for patients in whom MVD was their first surgical intervention. Patients who underwent initial MVD had improved pain relief and no improvement in pain rates compared with those who had subsequent MVD (95.8% and 4.2% vs 90.3% and 9.7%, respectively, p = 0.0041).

Patients who underwent initial MVD had significantly lower rates of facial numbness in the pre- and postoperative periods compared with patients who underwent subsequent MVD (p < 0.0001). The number of complications in both groups was similar (p = 0.4572).

CONCLUSIONS

The results demonstrate that patients who underwent other procedures prior to MVD had less pain relief and a higher incidence of facial numbness despite rates of complications similar to patients who underwent MVD as their first surgical intervention.

OBJECTIVE

The goal of this study was to investigate the local recurrence rate and long-term survival after resection of spinal sarcomas.

METHODS

A retrospective review of patients who underwent resection of primary or metastatic spinal sarcomas between 1997 and 2015 was performed. Tumors were classified according to the Enneking classification, and resection was categorized as Enneking appropriate (EA) if the specimen margins matched the Enneking recommendation, and as Enneking inappropriate (EI) if they did not match the recommendation. The primary outcome measure for all tumors was overall survival; local recurrence was also an outcome measure for primary sarcomas. The association between clinical, surgical, and molecular (tumor biomarker) factors and outcomes was also investigated.

CONCLUSIONS

The findings in the present study suggest that EA resection may be the strongest independent prognostic factor for improved survival in patients with spinal sarcoma. Additionally, patients who underwent EA resection had lower local recurrence rates. Patients 40 years or older, those with a history of previous radiation, and those with high-grade tumors had an increased hazard of mortality in this study.

OBJECT

A chordoma is an indolent primary spinal tumor that has devastating effects on the patient's life. These lesions are chemoresistant, resistant to conventional radiotherapy, and moderately sensitive to proton therapy; however, en bloc resection remains the preferred treatment for optimizing patient outcomes. While multiple small and largely retrospective studies have investigated the outcomes following en bloc resection of chordomas in the sacrum, there have been few large-scale studies on patients with chordomas of the mobile spine. The goal of this study was to review the outcomes of surgically treated patients with mobile spine chordomas at multiple international centers with respect to local recurrence and survival. This multiinstitutional retrospective study collected data between 1988 and 2012 about prognosis-predicting factors, including various clinical characteristics and surgical techniques for mobile spine chordoma. Tumors were classified according to the Enneking principles and analyzed in 2 treatment cohorts: Enneking-appropriate (EA) and Enneking-inappropriate (EI) cohorts. Patients were categorized as EA when the final pathological assessment of the margin matched the Enneking recommendation; otherwise, they were categorized as EI.

RESULTS

A total of 166 patients (55 female and 111 male patients) with mobile spine chordoma were included. The median patient follow-up was 2.6 years (range 1 day to 22.5 years). Fifty-eight (41%) patients were EA and 84 (59%) patients were EI. The type of biopsy (p < 0.001), spinal location (p = 0.018), and if the patient received adjuvant therapy (p < 0.001) were significantly different between the 2 cohorts. Overall, 58 (35%) patients developed local recurrence and 57 (34%) patients died. Median survival was 7.0 years postoperative: 8.4 years postoperative for EA patients and 6.4 years postoperative for EI patients (p = 0.023). The multivariate analysis showed that the EI cohort was significantly associated with an increased risk of local recurrence in comparison with the EA cohort (HR 7.02; 95% CI 2.96–16.6; p < 0.001), although no significant difference in survival was observed.

CONCLUSIONS

EA resection plays a major role in decreasing the risk for local recurrence in patients with chordoma of the mobile spine.

OBJECT

Calcium phosphate cement provides a biomaterial that can be used for calvarial reconstruction in a retrosigmoid craniectomy for microvascular decompression (MVD). This study evaluates the outcomes of postoperative CSF leak and wound infection for patients undergoing a complete cranioplasty using calcium phosphate cement versus incomplete cranioplasty using polyethylene titanium mesh following a retrosigmoid craniectomy for MVD.

METHODS

The authors evaluated 211 cases involving patients who underwent first-time retrosigmoid craniectomies performed by a single attending surgeon fortrigeminal neuralgia from October 2008 to June 2014. From this patient population, 111 patients underwent calvarial reconstruction after retrosigmoid craniectomy using polyethylene titanium mesh, and 100 patients had reconstructions using calcium phosphate cement. A Pearson’s chi-square test was used to compare postoperative complications of CSF leak and wound infection in these 2 types of cranioplasties.

RESULTS

The polyethylene titanium mesh group included 5 patients (4.5%) with postoperative CSF leak or pseudomeningocele and 3 patients (2.7%) with wound infections. In the calcium phosphate cement group, no patients had a CSF leak, and 2 patients (2%) had wound infections. This represented a statistically significant reduction of postoperative CSF leak in patients who underwent calcium phosphate reconstructions of their calvarial defect compared with those who underwent polyethylene titanium mesh reconstructions (p = 0.03). No significant difference was seen between the 2 groups in the number of patients with postoperative wound infections.

CONCLUSIONS

Calcium phosphate cement provides a viable alternative biomaterial for calvarial reconstruction of retrosigmoid craniectomy defects in patients who have an MVD. The application of this material provides a biocompatible barrier that reduces the incidence of postoperative CSF leaks.

OBJECT

The number of patients with spinal tumors is rapidly increasing; spinal metastases develop in more than 30% of cancer patients during the course of their illness. Such lesions can significantly decrease quality of life, often necessitating treatment. Stereotactic radiosurgery has effectively achieved local control and symptomatic relief for these patients. The authors determined prognostic factors that predicted pain palliation and report overall institutional outcomes after spine stereotactic body radiation therapy (SBRT).

METHODS

Records of patients who had undergone treatment with SBRT for either primary spinal tumors or spinal metastases from June 2008 through June 2013 were retrospectively reviewed. Data were collected at the initial visit just before treatment and at 1-, 3-, 6-, and 12-month follow-up visits. Collected clinical data included Karnofsky Performance Scale scores, pain status, presence of neurological deficits, and prior radiation exposure at the level of interest. Radiation treatment plan parameters (dose, fractionation, and target coverage) were recorded. To determine the initial extent of epidural spinal cord compression (ESCC), the authors retrospectively reviewed MR images, assessed spinal instability according to the Bilsky scale, and evaluated lesion progression after treatment.

RESULTS

The study included 99 patients (mean age 60.4 years). The median survival time was 9.1 months (95% CI 6.9–17.2 months). Significant decreases in the proportion of patients reporting pain were observed at 3 months (p < 0.0001), 6 months (p = 0.0002), and 12 months (p = 0.0019) after treatment. Significant decreases in the number of patients reporting pain were also observed at the last follow-up visit (p = 0.00020) (median follow-up time 6.1 months, range 1.0–56.6 months). Univariate analyses revealed that significant predictors of persistent pain after intervention were initial ESCC grade, stratified by a Bilsky grade of 1c (p = 0.0058); initial American Spinal Injury Association grade of D (p = 0.011); initial Karnofsky Performance Scale score, stratified by a score of 80 (p = 0.002); the presence of multiple treated lesions (p = 0.044); and prior radiation at the site of interest (p < 0.0001). However, when multivariate analyses were performed on all variables with p values less than 0.05, the only predictor of pain at last follow-up visit was a prior history of radiation at the site of interest (p = 0.0038), although initial ESCC grade trended toward significance (p = 0.073). Using pain outcomes at 3 months, at this follow-up time point, pain could be predicted by receipt of radiation above a threshold biologically effective dose of 66.7 Gy.

CONCLUSIONS

Pain palliation occurs as early as 3 months after treatment; significant differences in pain reporting are also observed at 6 and 12 months. Pain palliation is limited for patients with spinal tumors with epidural extension that deforms the cord and for patients who have previously received radiation to the same site. Further investigation into the optimal dose and fractionation schedule are needed, but improved outcomes were observed in patients who received radiation at a biologically effective dose (with an a/b of 3.0) of 66.7 Gy or higher.

OBJECT

Clinical outcomes in patients with primary spinal osteochondromas are limited to small series and sporadic case reports. The authors present data on the first long-term investigation of spinal osteochondroma cases.

METHODS

An international, multicenter ambispective study on primary spinal osteochondroma was performed. Patients were included if they were diagnosed with an osteochondroma of the spine and received surgical treatment between October 1996 and June 2012 with at least 1 follow-up. Perioperative prognostic variables, including patient age, tumor size, spinal level, and resection, were analyzed in reference to long-term local recurrence and survival. Tumor resections were compared using Enneking appropriate (EA) or Enneking inappropriate surgical margins.

RESULTS

Osteochondromas were diagnosed in 27 patients at an average age of 37 years. Twenty-two lesions were found in the mobile spine (cervical, thoracic, or lumbar) and 5 in the fixed spine (sacrum). Twenty-three cases (88%) were benign tumors (Enneking tumor Stages 1–3), whereas 3 (12%) exhibited malignant changes (Enneking tumor Stages IA–IIB). Sixteen patients (62%) underwent en bloc treatment—that is, wide or marginal resection—and 10 (38%) underwent intralesional resection. Twenty-four operations (92%) followed EA margins. No one received adjuvant therapy. Two patients (8%) experienced recurrences: one in the fixed spine and one in the mobile spine. Both recurrences occurred in latent Stage 1 tumors following en bloc resection. No osteochondroma-related deaths were observed.

CONCLUSIONS

In the present study, most patients underwent en bloc resection and were treated as EA cases. Both recurrences occurred in the Stage 1 tumor cohort. Therefore, although benign in character, osteochondromas still require careful management and thorough follow-up.